1 files changed, 150 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-hydra.c b/drivers/i2c/busses/i2c-hydra.c
new file mode 100644
index 0000000000..c60b73e933
--- /dev/null
+++ b/drivers/i2c/busses/i2c-hydra.c
@@ -0,0 +1,150 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+    i2c Support for the Apple `Hydra' Mac I/O
+
+    Copyright (c) 1999-2004 Geert Uytterhoeven <geert@linux-m68k.org>
+
+    Based on i2c Support for Via Technologies 82C586B South Bridge
+    Copyright (c) 1998, 1999 Kyösti Mälkki <kmalkki@cc.hut.fi>
+
+*/
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/types.h>
+#include <linux/i2c.h>
+#include <linux/i2c-algo-bit.h>
+#include <linux/io.h>
+#include <asm/hydra.h>
+
+
+#define HYDRA_CPD_PD0	0x00000001	/* CachePD lines */
+#define HYDRA_CPD_PD1	0x00000002
+#define HYDRA_CPD_PD2	0x00000004
+#define HYDRA_CPD_PD3	0x00000008
+
+#define HYDRA_SCLK	HYDRA_CPD_PD0
+#define HYDRA_SDAT	HYDRA_CPD_PD1
+#define HYDRA_SCLK_OE	0x00000010
+#define HYDRA_SDAT_OE	0x00000020
+
+static inline void pdregw(void *data, u32 val)
+{
+	struct Hydra *hydra = (struct Hydra *)data;
+	writel(val, &hydra->CachePD);
+}
+
+static inline u32 pdregr(void *data)
+{
+	struct Hydra *hydra = (struct Hydra *)data;
+	return readl(&hydra->CachePD);
+}
+
+static void hydra_bit_setscl(void *data, int state)
+{
+	u32 val = pdregr(data);
+	if (state)
+		val &= ~HYDRA_SCLK_OE;
+	else {
+		val &= ~HYDRA_SCLK;
+		val |= HYDRA_SCLK_OE;
+	}
+	pdregw(data, val);
+}
+
+static void hydra_bit_setsda(void *data, int state)
+{
+	u32 val = pdregr(data);
+	if (state)
+		val &= ~HYDRA_SDAT_OE;
+	else {
+		val &= ~HYDRA_SDAT;
+		val |= HYDRA_SDAT_OE;
+	}
+	pdregw(data, val);
+}
+
+static int hydra_bit_getscl(void *data)
+{
+	return (pdregr(data) & HYDRA_SCLK) != 0;
+}
+
+static int hydra_bit_getsda(void *data)
+{
+	return (pdregr(data) & HYDRA_SDAT) != 0;
+}
+
+/* ------------------------------------------------------------------------ */
+
+static struct i2c_algo_bit_data hydra_bit_data = {
+	.setsda		= hydra_bit_setsda,
+	.setscl		= hydra_bit_setscl,
+	.getsda		= hydra_bit_getsda,
+	.getscl		= hydra_bit_getscl,
+	.udelay		= 5,
+	.timeout	= HZ
+};
+
+static struct i2c_adapter hydra_adap = {
+	.owner		= THIS_MODULE,
+	.name		= "Hydra i2c",
+	.algo_data	= &hydra_bit_data,
+};
+
+static const struct pci_device_id hydra_ids[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_HYDRA) },
+	{ 0, }
+};
+
+MODULE_DEVICE_TABLE (pci, hydra_ids);
+
+static int hydra_probe(struct pci_dev *dev,
+				 const struct pci_device_id *id)
+{
+	unsigned long base = pci_resource_start(dev, 0);
+	int res;
+
+	if (!request_mem_region(base+offsetof(struct Hydra, CachePD), 4,
+				hydra_adap.name))
+		return -EBUSY;
+
+	hydra_bit_data.data = pci_ioremap_bar(dev, 0);
+	if (hydra_bit_data.data == NULL) {
+		release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
+		return -ENODEV;
+	}
+
+	pdregw(hydra_bit_data.data, 0);		/* clear SCLK_OE and SDAT_OE */
+	hydra_adap.dev.parent = &dev->dev;
+	res = i2c_bit_add_bus(&hydra_adap);
+	if (res < 0) {
+		iounmap(hydra_bit_data.data);
+		release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
+		return res;
+	}
+	return 0;
+}
+
+static void hydra_remove(struct pci_dev *dev)
+{
+	pdregw(hydra_bit_data.data, 0);		/* clear SCLK_OE and SDAT_OE */
+	i2c_del_adapter(&hydra_adap);
+	iounmap(hydra_bit_data.data);
+	release_mem_region(pci_resource_start(dev, 0)+
+			   offsetof(struct Hydra, CachePD), 4);
+}
+
+
+static struct pci_driver hydra_driver = {
+	.name		= "hydra_smbus",
+	.id_table	= hydra_ids,
+	.probe		= hydra_probe,
+	.remove		= hydra_remove,
+};
+
+module_pci_driver(hydra_driver);
+
+MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>");
+MODULE_DESCRIPTION("i2c for Apple Hydra Mac I/O");
+MODULE_LICENSE("GPL");